Calculators you can check, with the source shown.
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Every calculator you'll ever need, in one place
Work out your take-home pay, your mortgage repayments, your retirement savings, your BMI, a physics formula or a unit conversion, all in one place. Every tool is fast, clear and free, shows where its figures come from, and displays the date it was last checked. No sign-up, no paywall, nothing sold in between you and your answer.
Explore by category
Universal tools built once and shared, plus tax and finance tools localized to each jurisdiction.
- Tax & take-home pay Localized Federal income tax, state income tax, withholding, payroll and take-home pay for the US.
- Mortgage & property Localized Mortgage payments, affordability, PMI, FHA loans and property tax.
- Salary & payroll Localized Paychecks, payroll deductions, net pay, overtime and benefits.
- Loans & savings Universal Loan repayments, compound interest, CD rates and savings growth.
- Retirement & savings Localized 401k, IRA, HSA, FIRE, RMD, and Social Security planning.
- Insurance & actuarial Localized Life expectancy, premiums, loss ratios and coverage estimates.
- Maths & stats Universal Algebra, statistics, geometry, probability and number theory.
- Science & engineering Universal Physics, chemistry, biology and engineering tools.
- Unit converters Universal Length, weight, area, volume, temperature, energy and more.
- Health & fitness Universal BMI, BMR, body fat, nutrition and clinical calculators.
- Date & time Universal Date differences, age, working days and time zones.
Frequently asked questions
What CalculatorHub is, where the numbers come from, and how to use it.
Are the calculators free to use?
Yes. Every calculator on CalculatorHub is completely free, with no signup, login or paywall. Each tool runs in your browser, so nothing is installed and your inputs stay on your device.
Where do the numbers come from?
Published rates and reference figures trace to an official primary source where one exists (a government, state or local authority, a standards body, or peer-reviewed research). Where no universal official figure exists, we use a clearly labelled, editable assumption. Each tool lists its sources and the date the figures were last verified.
How many calculators are there?
About 6,700 distinct calculators, spanning tax, finance, health, fitness, math, science, engineering and unit conversions. Because each is published in multiple languages and the US tax and finance tools are localized to each state and county, that works out to 45,957 pages in total. Our methodology page explains how these are counted.
Do the calculators work on mobile?
Yes. Every tool is mobile-first and works in any modern browser. There is no app to install and the interface adapts to phones, tablets and desktops.
Can I rely on the results for important decisions?
The math is deterministic and each formula is tested against a worked example before it ships. Anything we cannot confirm is shown as an editable input rather than an asserted value. For regulated or high-stakes decisions, always confirm against the official source we link.